Amelia Earhart raised the spirits of Depression-era America as she soared into the aviation record books with feats of altitude, distance and endurance. The mood took a gloomy turn, however, when she and her navigator Fred Noonan disappeared over the Pacific Ocean on July 2, 1937, during a much-heralded attempt to fly around the world. Their fate remains one of aviation’s greatest unsolved mysteries.

Theories abound: They ran out of fuel and crashed into the Pacific Ocean. They were captured by the Japanese and executed. They survived, and Earhart lived out her life as a housewife in New Jersey.

A prominent theory with tantalizing clues holds that they survived the crash landing and but perished as castaways on Nikumaroro, an uninhabited island in the republic of Kiribati. An expedition to the island in 2010 recovered pieces of a pocket knife and a glass jar that may have belonged to the castaways. If DNA analyses on these and other items match Earhart’s, the mystery may finally be resolved.

Wisps of clouds form a honeycomb-like structure (center) over the Peruvian coast.

Such open-cell marine clouds “communicate” with each other so that they constantly oscillate, or rearrange themselves, in a synchronized pattern, according to a new study from the U.S. National Oceanic and Atmospheric Administration (NOAA).

Inside the thick clouds of the cell walls, water droplets grow, then fall as rain, and the walls dissipate. The raindrops evaporate as they fall, cooling the air, which generates downward air currents.

When the downdrafts hit the ocean surface, they flow outward and collide with each other and “force the air to move upward again” and “form new open cell walls at a different location,” explained study co-author Hailong Wang, a cloud physicist at the Pacific Northwest National Laboratory in Richland, Washington.

The inside of the moon isn’t as watery as previously reported, according to a new study that found a high variety of chlorine atoms in Apollo moon rocks.

For decades scientists had thought the moon is bone dry inside and out. But recent moon-impact missions found water ice on the lunar surface, and reanalysis of rocks brought back by Apollo astronauts found evidence for significant amounts of water inside the moon in the form of hydroxyl (-OH), a hydrogen compound formed by the breakdown of water (H2O).

In a new study of Apollo moon rocks, geochemist Zachary Sharp of the University of New Mexico and colleagues measured the moon rocks’ chlorine isotopes, or different forms of the chlorine atom.